DENVER — Investigators looking into the shooting death of the director of the Colorado Department of Corrections will look at the possibility that Tom Clements’ murder may be tied to the recent decision not to grant a transfer of a Saudi man in a Colorado prison.

Homaidan Al-Turki was convicted in 2006 of unlawful sexual contact by use of force and other charges. Prosecutors said he sexually assaulted a housekeeper and kept her as a virtual slave for four years.

His conviction angered Saudi officials. The U.S. State Department sent Colorado Attorney General John Suthers to Saudi Arabia to meet with King Abdullah, Crown Prince Sultan and Al-Turki’s family.

Last week, Colorado prison officials denied a request from the Saudi Arabian government to release Al-Turki to his home country to serve his life sentence.

Prosecutors opposed Al-Turki’s transfer fearing he would be released upon return to Saudi Arabia.

Celments was the one who decided to deny the transfer. He wrote in a letter to Al-Turki that because Al-Turki refused to undergo sex offender treatment in prison, “I have decided not to support your request for transfer to Saudi Arabia at this time,” reported the Associated Press.

A source familiar with the investigation who refused to be identified by name because they were not authorized to speak publicly about the case, said the Al-Turki connection right now is the main working theory behind Clements death.

The source also said other people involved in the Al-Turki case have been contacted by law enforcement and are now getting extra protection.

The U.S. Attorney for Colorado John Walsh received extra security at his house Tuesday night and was escorted to work Wednesday under armed guard, a high-placed law enforcement source told FOX31 Denver reporter Justin Joseph.

Investigators have admitted they don’t have much to go on at this point and will look at all possibilities.

Clement’s wife was home when he was shot, but told police she did not see anything.

Authorities are looking for a boxy-style, dark-colored, 2-door, 90s-model vehicle running unoccupied and parked at an intersection near the scene of the shooting.

Gov. John Hickenlooper ordered flags to be lowered to half-staff at all public buildings statewide. Flags will remain at half-staff until the day after Clements funeral.